Site-selective thionation and doping enabled tunable full-color emission in nonconventional luminophores

Nonconventional luminophores have gained significant attention for their distinctive luminescence behaviors and promising applications. However, achieving precise control over their photoluminescence (PL) remains a substantial challenge. Current strategies for structural modification remain largely semi-empirical, lacking robust frameworks to effectively correlate molecular-level variations with aggregate states and their corresponding PL. In this study, we demonstrate tunable full-color emission (blue to red) with a high quantum yield of up to 58.9%, through site-selective thiolation of hydantoin (HA) and subsequent host-guest doping. We elucidate the thionation effect on both individual molecules and their molecular arrangements, revealing that CS groups and parallel molecular arrangement promote extensive electron delocalization and redshifted PL. Leveraging the structural and packing similarity between the host and guest, we achieve fine-tuning of PL by doping thionated molecules into HA and thiazolidinedione crystals, establishing a direct structure-property relationship without requiring complex molecular redesign. Furthermore, we showcase the applicability of these luminophores in advanced anti-counterfeiting, information encryption and high-resolution visualization of latent fingerprints. This research offers novel insights and broadly applicable strategies for achieving tunable emission in nonconventional luminophores by precisely controlling electronic structures and molecular arrangement.